The health risks mentioned in this article seem to revolve around allergic reactions, and the effects tattoos can have on the immune system. It appears about 6% of the general population end up with chronic problems. I would guess the percentage would be much higher for pwME/SEID. In Addition To Regret, Tattoos Can Pose Serious Health Risks Here's a few major points from the article About 1 in 10 people who get tattoos experiences problems with the tattoo, including infection, itching, swelling and redness, according to a small study in the June issue of the journal Contact Dermatitis. Many people in the study had complications that lingered for years after the tattoo was inked, the researchers said.... - About 10 percent of the people said they'd had some complications. For some, these complications were short-lived, such as bacterial infection right after the tattoo was inked, or temporary swelling and itching. But of those who had complaints, six in 10 suffered from chronic problems. And although many had suffered from unpleasant itching or swelling for years, few had bothered to get their problems checked by a doctor, the researchers found... - Although tattoo artists and parlors are strictly regulated in order to limit infection and disease transmission risk, few people know what is in the tattoo ink itself. — "Tattoo inks aren't very closely regulated in the United States," Leger told Live Science. - "Some of the stories we got do definitely sound like tattoo allergy," Leger said. "They'll have a red tattoo, and then a few years later, they will get a new tattoo — and, all of a sudden, the new red and the old red tattoo become itchy and raised."